KR20100117030A - Liquid-crystal display - Google Patents

Abstract

PURPOSE: A liquid crystal medium is provided to set the low pretilt angle, and to secure the extremely high specific resistance value and the high voltage holding ratio value. CONSTITUTION: A liquid crystal medium including more than one compound marked with chemical formula I, is applied to a liquid crystal display of either a polymer stabilization type, or a queue continuing polymer type. In the chemical formula I, R1 and R2 are alkyl with 1~12 carbons, respectively. A1, A2, A3, and A4 are functional groups marked with either chemical formula I-a or I-b.

Description

Liquid Crystal Display {LIQUID-CRYSTAL DISPLAY}

The present invention relates to LC media used in liquid crystal (LC) displays of the PS (polymer-stabilized) or PSA (polymer-sustained alignment) type.

Currently used liquid crystal displays (LC displays) are generally TN (twisted nematic) type displays. However, such displays have the disadvantage that the viewing angle dependence of contrast is strong.

In addition, so-called VA (vertical alignment) displays with a wide viewing angle are also known. The LC cell of the VA display contains a layer of LC medium with a generally negative (DC) anisotropy between the two transparent electrodes. In the switched-off state, the molecules of the LC layer are aligned perpendicular to the electrode surface (homeotropically) or have an inclined homeotropic alignment. When a voltage is applied to the electrode, the LC molecules are rearranged parallel to the electrode surface.

In addition, OCB (optical compensation bend) displays with so-called "bend" alignment and LC layers with generally positive (DC) anisotropy, based on birefringent effects, are known. When a voltage is applied, the LC molecules are rearranged perpendicular to the electrode surface. In addition, OCB displays typically contain one or more birefringent optical retardation films to prevent unwanted light transmission of the bend cell in the dark state. OCB displays have a wider viewing angle and shorter response time than TN displays.

Also commonly known are IPS (planar switching) displays having a comb-shaped structure, generally containing an LC layer between two substrates, only one of which has an electrode layer. When a voltage is applied, an electric field with a principal component parallel to the LC layer is produced. This causes realignment of the LC molecules in the layer plane. Furthermore, similarly it contains two electrodes on the same substrate, but unlike IPS displays, only one of them is a structured (comb-shaped) electrode and the other electrode is of an unstructured form, called a FFS (fringe) Field switching) is also proposed (see, in particular, SHJung et al., Jpn. J. Appl. Phys., Volume 43, No. 3, 2004, 1028). This produces a so-called strong " fringe field ", i.e., a strong electric field close to the edge of the electrode and an electric field having both a strong vertical component and a strong horizontal component throughout the cell. Both IPS displays and FFS displays have low viewing angle dependence of contrast.

For more recent types of VA displays, the uniform alignment of the LC molecules is limited to many relatively small domains in the LC cell. There may also be disclination between these domains, also known as tilt domains. VA displays with tilt domains have greater viewing angle dependence of contrast and grayscale compared to conventional VA displays. In addition, this type of display is simple to manufacture because no further processing of the electrode surface, such as for example rubbing, is required for uniform alignment of molecules in the switched-on state. Can be. Instead, the preferential direction of the tilt or pretilt angle is controlled by the unique design of the electrode. In the case of so-called MVA (multi-domain vertical alignment) displays, this is generally achieved by electrodes having protrusions that cause local pretilt. As a result, LC molecules are aligned parallel to the electrode surface in different directions within differently defined cell regions by application of voltage. This achieves “controlled” switching and prevents the formation of interfering disclination lines. This arrangement improves the viewing angle of the display, but reduces its light transmittance. A further improvement of the MVA uses protrusions on only one electrode face, while the opposite electrode improves light transmission by having a slit. Electrodes with slits generate a non-uniform electric field in the LC cell by application of a voltage, which means that controlled switching is still achieved. Although the light transmission can be further improved by increasing the distance between the slit and the protrusion, this actually results in extending the response time. In the case of so-called PVA (patterned VA), the contrast is increased and light transmission is improved by structuring both electrodes by slits on the opposite side, but this is technically difficult and the display is not affected by mechanical influences (tapping, etc.). The protrusions are completely unnecessary in that they become more sensitive. However, for many applications, for example monitors, in particular TV screens, there is a need for shortening the response time of the display and improving the contrast and luminance (transmission).

Further so-called PS (polymer-stabilized) displays, also known as PSA (polymer-sustained alignment), have been further developed. In these cases, a small amount (eg 0.3% by weight, typically less than 1% by weight) of polymerizable compound is added to the LC medium and introduced into the LC cell, followed by UV photopolymerization, usually by applying an electrical voltage between the electrodes. By polymerization or crosslinking in situ. In addition, addition of polymerizable mesogenic or liquid crystalline compounds, also known as "reactive mesogens (RM)", has proven particularly suitable.

On the other hand, the PSA principle has been used in various conventional LC displays. For example, PSA-VA, PSA-OCB, PS-IPS / FFS and PS-TN displays are known. The polymerization of the polymerizable compound (s) takes place preferably by the application of voltage in the case of PSA-VA and PSA-OCB displays, but in the case of PSA-IPS displays by application of voltage or without Occurs without. As can be demonstrated in the test cell, the PSA method produces pretilt in the cell. Therefore, in the case of the PSA-OCB display, the bend structure can be stabilized so that an offset voltage can be unnecessary or reduced. For PSA-VA displays, this pretilt has a positive effect on response time. For PSA-VA displays, standard MVA or PVA pixel and electrode designs can be used. However, in addition, for example, by operating with only one structured electrode face and no protrusion at all, it is possible to significantly simplify production and at the same time obtain very good contrast and very good light transmission.

PSA-VA displays are for example JP 10-036847 A, EP 1 170 626 A2, EP 1 378 557 A1, EP 1 498 468 A1, US 2004/0191428 A1, US 2006/0066793 A1 and US 2006/0103804 A1 It is described in PSA-OCB displays are described, for example, in T. -J-. Chen et al., Jpn. J. Appl. Phys. 45, 2006, 2702-2704 and S. H. Kim, L. -C-. Chien, Jpn. J. Appl. Phys. 43, 2004, 7643-7647. PS-IPS displays are described, for example, in US Pat. No. 6,177,972 and Appl. Phys. Lett. 1999, 75 (21), 3264. PS-TN displays are described, for example, in Optics Express 2004, 12 (7), 1221.

Similar to the conventional LC display described above, the PSA display can be operated as an active-matrix or passive-matrix display. In the case of active-matrix displays, the individual pixels are generally addressed through integrated non-linear active elements such as, for example, transistors (eg thin film transistors, "TFTs"), and in the case of passive-matrix displays, they are generally It is addressed in a multiplexing manner known in the art.

Specifically, for monitors, especially TV applications, optimization of contrast and brightness (also transmission) as well as response time of LC displays is still required. The PSA method can provide a decisive advantage here. Particularly in the case of PSA-VA, the shortening of the response time correlated with the measurable pretilt in the test cell can be achieved without significantly affecting other parameters.

However, LC mixtures and RMs known in the art have been found to still have some drawbacks when used in PSA displays. Thus, the desired available mode RM is not suitable for PSA displays, and it is often difficult to identify more suitable selection criteria than direct PSA experiments by pretilt measurements. If polymerization by UV light is desired without the addition of photoinitiators, which may be beneficial for certain applications, the choice is much smaller. In addition, LC mixtures (also referred to as "LC host mixtures") + polymerizable component "material systems" have the lowest possible rotational viscosity and the best possible electrical properties, in particular "voltage retention" (VHR or HR). Should be chosen. With regard to PSA displays, high VHR after irradiation with UV light is particularly important because UV exposure is a necessary part of the display manufacturing process, but it also manifests itself essentially as "normal" exposure in the final display.

However, combinations of all LC mixtures + polymerizable components are particularly suitable for PSA displays, for example, due to inadequate tilt or no tilt at all, or for example because VHR is inadequate for TFT display applications.

In particular, it would be desirable to have new materials useful for PSA displays that produce significantly lower pretilt angles. A shorter time for a (higher) pretilt angle that could have been achieved using known materials through the use of materials known to be lower, and / or through use thereof, during polymerization during the same exposure time. It would be particularly desirable to be able to achieve already. Thus, the manufacturing time (tact time) of the display may be shortened and the manufacturing process cost may be reduced. The faster polymerization rate of the RMs is also particularly advantageous for the arrangement, where appropriate, allowing the remaining amount of non-polymerized RMs still present to react as quickly as possible after the tilt angle is established. The presence of unreacted RMs on the display can adversely affect the display characteristics. Thus, in addition to the rapid polymerization of RMs, the most complete polymerization of RMs is also preferred if possible.

Thus, there is still a significant need for PSA displays, especially VA and OCB type displays, and LC media and polymerizable compounds for use in such displays, which do not have the disadvantages described above, have only a small extent or have improved properties. . In particular, it promotes high resistivity, wide working-temperature range, short response time at low temperatures, low threshold voltage, low pretilt angle, multiple shades of gray, high contrast and wide viewing angle, and high voltage retention (VHR) values after UV exposure. There is a significant need for PSA displays or materials used in PSA displays.

It is an object of the present invention to set a low pretilt angle, preferably at the same time having very high resistivity values, high VHR values, low threshold voltages and short response times, with or without only the disadvantages described above. To provide a novel LC medium for use in PSA displays.

This object is achieved by the LC medium and LC display according to the invention described herein. In particular surprisingly, the use of the LC medium according to the invention in PSA displays facilitates particularly quick setting of low pretilt angles and desired tilt angles. This was demonstrated by measuring the pretilt in relation to the LC medium. In particular, pretilt was achieved without adding a photoinitiator. In addition, as evidenced by the exposure time-dependent measurement of the pretilt angle, the material according to the invention exhibits much faster pretilt angle generation than the materials known in the art. It has also been found that when using other LC media in the present invention, both the polymerization rate and polymerization integrity of the RMs increased significantly over the LC media known in the art. This allows for shorter exposure times and thus more efficient and economical process performance and a reduction in the amount of unwanted non-polymerized RMs on the display.

The present invention relates to the use of an LC mixture comprising at least one compound of the formula (I) in a liquid crystal (LC) display of the PS (polymer stabilization) or PSA (polymer sustained alignment) type:

[Formula I]

Each radical in the formula has the following meanings:

R ¹ and R ² each independently represent an alkyl having from 1 to 12 carbon atoms, wherein also one or two non-adjacent CH ₂ groups are -O-, -CH in such a way that the O atoms are not directly connected to each other. May be replaced by = CH-, -CO-, -OCO- or -COO-, preferably alkyl or alkoxy having 1 to 6 carbon atoms,

또는

를 나타내고,A ¹ , A ² , A ³ and A ⁴ are each independently of the other

or

Lt; / RTI >

또는

를 나타내고,1, 2 or 3 of A ¹ , A ² , A ³ and A ⁴ are also

or

Lt; / RTI >

L ¹ and L ² each independently represent H, F, Cl, OCF ₃ , CF ₃ , CH ₂ F or CHF ₂ ,

Z ^1, Z ² and Z ³ are each independently _{-COO-, -OCO-, -CF 2 O-,} -OCF 2 each other _{-, -CH 2 O-, -OCH 2} -, -SCH 2 -, -CH ₂ S-, -CH ₂ CH _2- , -C ₂ F _4- , -CH ₂ -CF _2- , -CF ₂ CH ₂ -,-(CH ₂ ) _z- , -CH = CH-, -CF = CF—, —CH═CF—, —CF═CH—, —C≡C—, —CH═CHCH ₂ O—, or a single bond, where m = 0, Z ¹ and Z ² are simultaneously single Does not represent a bond,

z represents 3, 4, 5 or 6,

m represents 0 or 1.

The present invention furthermore relates to an LC medium comprising an LC mixture according to the invention as described above and below and preferably at least one polymerizable compound selected from the group consisting of reactive mesogens.

The invention furthermore relates to an LC medium comprising a polymer obtainable by polymerization of an LC mixture according to the invention as described above and below and preferably at least one polymerizable compound selected from the group consisting of reactive mesogens. It is about.

The invention also relates to an LC medium comprising the following components:

A polymerizable component A) preferably comprising at least one polymerizable compound selected from reactive mesogens, and

Liquid crystal component B) consisting of an LC mixture according to the invention comprising at least one compound of the formula (I) as described above and below (hereinafter also referred to as "LC host mixture").

The invention also relates to an LC medium comprising the following components:

Polymers obtainable by polymerization of polymerizable component A), preferably comprising at least one polymerizable compound selected from reactive mesogens, and

Liquid crystal component B) consisting of an LC mixture according to the invention comprising at least one compound of the formula (I) as described above and below (hereinafter also referred to as "LC host mixture").

The present invention furthermore provides for the use of LC mixtures and LC media according to the invention in PS and PSA displays, in particular by in situ polymerization of the polymerizable compound (s) in the PSA display by application of an electric or magnetic field to produce a tilt angle in the LC medium. The present invention relates to the use of PS and PSA displays containing LC media.

The invention also relates to an LC display, in particular a PS or PSA display, particularly preferably a PSA-VA, PS-IPS or PS-FFS display, containing an LC medium according to the invention.

The present invention also provides two substrates, wherein at least one substrate is translucent and at least one substrate is an electrode layer; And a polymerized component located between the substrates and obtainable by polymerizing one or more polymerizable compounds in an LC medium between the substrates of an LC cell by the application of a voltage, and an LC mixture as described above and below A LC display of the PS or PSA type containing an LC cell composed of a layer of LC medium comprising a phosphorus low-molecular weight component.

The invention furthermore relates to a process for preparing an LC medium according to the invention by mixing at least one low-molecular weight liquid crystal compound or LC mixture according to the invention with at least one polymerizable compound and optionally further liquid crystal compounds and / or additives. It is about.

The invention furthermore relates to mixing the LC mixture according to the invention with at least one polymerizable compound and optionally further liquid crystal compounds and / or additives, introducing the resulting mixture into the LC cell as described above and below, A process for producing an LC display according to the invention by polymerizing polymerizable compound (s) by application of voltage.

The following meanings apply above and below.

The term "PSA" refers to PS displays and PSA displays unless otherwise indicated.

The terms "tilt" and "tilt angle" relate to the inclined alignment of LC molecules of the LC medium with respect to the cell surface in the LC display (preferably herein PS or PSA display). “Tilt angle” herein refers to the average angle (<90 °) between the longitudinal molecular axis of LC molecules (LC director) and the surface-parallel outer plate surface forming the LC cell. A low value of tilt angle (i.e. a lot of deviation from an angle of 90 °) corresponds to a large tilt. Suitable methods for measuring the tilt angle are presented in the examples. Unless stated otherwise, the angle values discussed above and below relate to this measuring method.

The term “mesogenic group” is known to the person skilled in the art and described in the literature and is essential for inducing a liquid crystal phase in low-molecular weight or polymeric materials due to its anisotropy and attraction of repulsive interactions. Represents a group contributing to Compounds containing mesogenic groups (mesogenic compounds) do not necessarily have to have an LC phase themselves. In addition, mesogenic compounds may exhibit LC phase behavior only after mixing with other compounds and / or after polymerization. Typical mesogenic groups are, for example, rigid rod-shaped or disc-shaped units. For an overview of the terms and definitions used in connection with mesogenic or LC compounds, see Pure Appl. Chem. 73 (5), 888 (2001) and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116, 6340-6368.

The term “spacer group”, also referred to above and hereinafter as “Sp”, is known to those skilled in the art, for example in Pure Appl. Chem. 73 (5), 888 (2001) and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116, 6340-6368. Unless otherwise indicated, the terms "spacer group" or "spacer" above and below denote flexible groups that connect mesogenic groups and polymerizable group (s) to each other in a polymerizable mesogenic compound.

The term "reactive mesogen" or "RM" refers to a compound containing a mesogenic group or one or more functional groups (also referred to as polymerizable groups or P groups) suitable for polymerization.

The terms "low-molecular weight compound" and "non-polymerizable compound" are generally monomeric compounds which do not contain any functional groups suitable for polymerization under ordinary conditions known to those skilled in the art, especially those used for the polymerization of RMs. Indicates.

For the purposes of the present invention, the term "LC medium" is intended to denote a medium comprising an LC mixture and one or more polymerizable compounds (eg reactive mesogens). The term "LC mixture" (or "host mixture") is intended to denote a liquid crystal mixture consisting of non-polymerizable low-molecular weight compounds, preferably two or more liquid crystal compounds and optionally additional additives such as chiral dopants or stabilizers. . "Non-polymerizable" means a state in which the compound is stable or non-reactive with respect to the polymerization reaction at least under the conditions used for the polymerization of the polymerizable compounds.

Particular preference is given to LC mixtures and LC media having nematic phases, especially at room temperature.

The concentration of the compound of formula (I) in the LC mixture (ie no polymerizable component) is preferably at least 1%, particularly preferably from 1 to 25%, very particularly preferably from 2 to 10%.

Particular preference is given to LC mixtures and LC media comprising 1 to 5, preferably 1, 2 or 3 compounds of formula (I).

Particular preference is given to compounds of the formula (I) having the meanings given below:

L ¹ and L ² represent H, F or Cl,

Z ¹ , Z ² and Z ³ are —COO—, —OCO—, —CF ₂ O—, —CH ₂ O—, —OCH ₂ — and a single bond, in particular —COO—, —CH ₂ O— and a single Selected from the group consisting of bonds,

Z ¹ and / or Z ³ represent a single bond,

m is 0, Z ¹ represents a single bond, Z ² is a non-single bond,

m is 0 and Z ² represents -COO-,

m is 0 and Z ² represents -CH ₂ O-,

m is 1 and Z ² represents -COO-

m is 1 and Z ² represents -CH ₂ O-,

m is 1 and Z ² represents a single bond,

m is 1 and Z ¹ , Z ² and Z ³ represent a single bond,

또는

로부터 선택되며, 여기서 L¹ 및 L²는 상기 기재된 의미를 가지고, 바람직하게는 H 또는 F를 나타내고,-A ¹ , A ² , A ³ and A ⁴

or

Wherein L ¹ and L ² have the meanings described above, preferably represent H or F,

At least one of the radicals A ¹ , A ² , A ³ and A ⁴ , particularly preferably at least A ¹ is trans-1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydroparan-1, 4-diyl or tetrahydroparan-2,5-diyl;

R ¹ and R ² represent straight chain alkyl or alkoxy having 1 to 12 carbon atoms, or straight chain alkenyl having 2 to 7 carbon atoms.

The compound of formula I is preferably selected from the group consisting of the compounds of the following sub-formulas I1 to I15:

Where

Alkyl and alkyl ^* each independently represent a straight chain alkyl radical having 1 to 12, preferably 1 to 6 carbon atoms, (O) represents an oxygen atom or a single bond, and (CH = CH) represents Nylene group or a single bond, and L represents H or F.

Particular preference is given to compounds selected from the group consisting of the formulas I1, I2, I3, I4, I5, I6, I7, I8 and I9, in particular compounds of the formula I1, I2, I3 or I4.

Preferred alkyl groups are, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, n-hexyl, 2-ethylhexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl.

Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl.

Preferred alkoxy groups are, for example, methoxy, ethoxy, 2-methoxy-ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy , 2-methylbutoxy, n-pentyloxy, n-hexyloxy, n-heptyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, n-undecyloxy, n-dodecyloxy to be.

Particularly preferred LC mixtures, LC media and LC displays are shown below:

1) LC mixture or LC medium further comprising at least one compound of the formulas CY and / or PY:

[Formula CY]

[Formula PY]

Wherein each radical has the following meaning:

a represents 1 or 2,

b represents 0 or 1,

는

를 나타내고,

Is

Lt; / RTI &gt;

R ¹ and R ² each independently represent an alkyl having from 1 to 12 carbon atoms, wherein also one or two non-adjacent CH ₂ groups are -O-,-in such a way that the O atoms are not directly connected to each other. May be replaced by CH═CH—, —CO—, —OCO— or —COO—, preferably alkyl or alkoxy having 1 to 6 carbon atoms,

Z ^x and Z ^y are each independently from each other -CH ₂ CH _{2 -, -CH = CH-, -CF 2} O-, -OCF 2 -, -CH 2 O-, -OCH 2 -, -COO-, - OCO—, —C ₂ F ₄ —, —CF═CF—, —CH═CHCH ₂ O— or a single bond, preferably a single bond,

L ¹ To L ⁴ each independently represent F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F or CHF ₂ .

Preferably, the radicals L ¹ and L ² All represent F or one of the radicals L ¹ and L ² represents F and the other represents Cl or the radicals L ³ and L ⁴ Both represent F or the radicals L ³ and L ⁴ One represents F and the other represents Cl.

The compound of formula CY is preferably selected from the group consisting of the compounds of the following subformulas CY1 to CY31:

Where

a represents 1 or 2, alkyl and alkyl ^* each independently represent a straight chain alkyl radical having 1 to 6 carbon atoms, alkenyl represents a straight chain alkenyl radical having 2 to 6 carbon atoms, ( O) represents an oxygen atom or a single bond. Alkenyl is preferably CH ₂ = CH-, CH ₂ = CHCH ₂ CH _2- , CH ₃ -CH = CH-, CH ₃ -CH ₂ -CH = CH-, CH _3- (CH ₂ ) ₂ -CH = CH-, CH _3- (CH ₂ ) ₃ -CH = CH- or CH ₃ -CH = CH- (CH ₂ ) _2- .

The compound of formula PY is preferably selected from the group consisting of the compounds of the following sub-formulas PY1 to PY20:

Where

Alkyl and alkyl ^* each independently represent a straight chain alkyl radical having 1 to 6 carbon atoms, alkenyl represents a straight chain alkenyl radical having 2 to 6 carbon atoms, and (O) represents an oxygen atom or a single bond Indicates. Alkenyl is preferably CH ₂ = CH-, CH ₂ = CHCH ₂ CH _2- , CH ₃ -CH = CH-, CH ₃ -CH ₂ -CH = CH-, CH _3- (CH ₂ ) ₂ -CH = CH-, CH _3- (CH ₂ ) ₃ -CH = CH- or CH ₃ -CH = CH- (CH ₂ ) _2- .

The concentration of each of the mixtures of formula CY or PY in the LC mixture is preferably from 2 to 20%.

The total concentration of the compounds of the formulas CY and PY in the LC mixture is preferably 1 to 99%, particularly preferably 10 to 70%.

2) LC mixture or LC medium further comprising at least one compound of the formula ZK:

[Formula ZK]

Wherein each radical has the following meaning:

는

를 나타내고,

Is

Lt; / RTI &gt;

는 를 나타내고,

Is Lt; / RTI &gt;

R ³ and R ⁴ are each independently alkyl having 1 to 12 carbon atoms, wherein also one or two non-adjacent CH ₂ groups are -O-, -CH in such a way that the O atoms are not directly connected to each other. May be replaced by = CH-, -CO-, -OCO- or -COO-,

^Y Z is _{-CH 2 CH 2 -, -CH =} CH-, -CF 2 O-, -OCF 2 -, -CH 2 O-, -OCH 2 -, -COO-, -OCO-, -C 2 F _4- , -CF = CF-, -CH = CHCH ₂ O- or a single bond, preferably a single bond.

The compound of formula ZK is preferably selected from the group consisting of the compounds of the following subformulas ZK1 to ZK10:

Where

Alkyl and alkyl ^* each independently represent a straight chain alkyl radical having 1 to 6 carbon atoms, and alkenyl represents a straight chain alkenyl radical having 2 to 6 carbon atoms. Alkenyl is preferably CH ₂ = CH-, CH ₂ = CHCH ₂ CH _2- , CH ₃ -CH = CH-, CH ₃ -CH ₂ -CH = CH-, CH _3- (CH ₂ ) ₂ -CH = CH-, CH _3- (CH ₂ ) ₃ -CH = CH- or CH ₃ -CH = CH- (CH ₂ ) _2- .

The concentration of each compound of formula ZK in the LC mixture is preferably from 2 to 20%.

3) LC mixture or LC medium further comprising at least one compound of the formula DK:

[Formula DK]

Each radical in the formula has the same meaning in each case to be the same or different:

R ⁵ and R ⁶ has one of the meanings described for R ¹ independently from each other, respectively,

는

를 나타내고,

Is

Lt; / RTI &gt;

는

를 나타낸다.

Is

Indicates.

The compound of formula DK is preferably selected from the group consisting of the compounds of the following sub-formula DK1 to DK8:

Where

Alkyl and alkyl ^* each independently represent a straight chain alkyl radical having 1 to 6 carbon atoms, and alkenyl and alkenyl ^* each independently represent a straight chain alkenyl radical having 2 to 6 carbon atoms. Alkenyl and alkenyl ^* are preferably CH ₂ = CH-, CH ₂ = CHCH ₂ CH _2- , CH ₃ -CH = CH-, CH ₃ -CH ₂ -CH = CH-, CH _3- (CH ₂ ) ₂ -CH = CH-, CH _3- (CH ₂ ) ₃ -CH = CH- or CH ₃ -CH = CH- (CH ₂ ) _2- .

Particular preference is given to compounds of the formulas DK1, DK2, DK4 and DK5.

4) LC mixture or LC medium further comprising at least one compound of the formula LY:

[Formula LY]

Each radical in the formula has the following meanings:

는

를 나타내고,

Is

Lt; / RTI &gt;

f represents 0 or 1,

R ¹ and R ² each independently represent an alkyl having from 1 to 12 carbon atoms, wherein also one or two non-adjacent CH ₂ groups are -O-,-in such a way that the O atoms are not directly connected to each other. May be replaced by CH = CH-, -CO-, -OCO- or -COO-,

Z ^x and Z ^y are each independently from each other -CH ₂ CH _{2 -, -CH = CH-, -CF 2} O-, -OCF 2 -, -CH 2 O-, -OCH 2 -, -COO-, - OCO—, —C ₂ F ₄ —, —CF═CF—, —CH═CHCH ₂ O— or a single bond, preferably a single bond,

L ¹ And L ² each independently represent F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F or CHF ₂ .

Preferably, the radical L ¹ And L ² both represent F or radical L ¹ And L ² One represents F and the other represents Cl.

The compound of formula LY is preferably selected from the following subformulas LY1 to LY18:

Where

R ¹ has the meaning described above, alkyl represents a straight chain alkyl radical having 1 to 6 carbon atoms, (O) represents an oxygen atom or a single bond, and v represents an integer from 1 to 6. R ¹ is preferably straight chain alkyl having 1 to 6 carbon atoms or straight chain alkenyl having 2 to 6 carbon atoms, in particular CH ₃ , C ₂ H ₅ , nC ₃ H ₇ , nC ₄ H ₉ , nC ₅ H ₁₁ , CH ₂ = CH-, CH ₂ = CHCH ₂ CH _2- , CH ₃ -CH = CH-, CH ₃ -CH ₂ -CH = CH-, CH _3- (CH ₂ ) ₂ -CH = CH- , CH _3- (CH ₂ ) ₃ -CH = CH- or CH ₃ -CH = CH- (CH ₂ ) _2- .

The concentration of each compound of formula LY in the LC mixture is preferably from 2 to 20%.

5) LC mixture or LC medium further comprising at least one compound selected from formulas G1 to G4:

Where

Alkyl is C _{1 -6} - represents alkyl, L ^* represents H or F, X is F, Cl, OCF _3, OCHF _2, or represents the OCH = CF _2.

Particular preference is given to compounds of the formula G1 in which X represents F.

6) LC mixture or LC medium further comprising at least one compound selected from formulas Y1 to Y16:

Where

R ⁵ is for R ¹ has one of the meanings set forth, alkyl is C _{1 -6} - represents an alkyl, d is 0 or 1, z and m represents an integer of 1 to 6, each independently from each other.

In these compounds, R ⁵ is particularly preferably a C _{1 -6-alkyl} or -alkoxy or C _{2 -6-alkenyl,} and, d is preferably 1. The LC medium according to the invention preferably comprises at least 5% by weight of at least one compound of the above-mentioned formula.

7) LC mixture or LC medium further comprising at least one biphenyl compound of formula B1 to B3:

Where

Alkyl and alkyl ^* each independently represent a straight chain alkyl radical having 1 to 6 carbon atoms, and alkenyl and alkenyl ^* each independently represent a straight chain alkenyl radical having 2 to 6 carbon atoms. Alkenyl and alkenyl ^* are preferably CH ₂ = CH-, CH ₂ = CHCH ₂ CH _2- , CH ₃ -CH = CH-, CH ₃ -CH ₂ -CH = CH-, CH _3- (CH ₂ ) ₂ -CH = CH-, CH _3- (CH ₂ ) ₃ -CH = CH- or CH ₃ -CH = CH- (CH ₂ ) _2- .

The proportion of biphenyls of the formulas B1 to B3 in the LC mixture is preferably at least 3% by weight, in particular at least 5% by weight.

Particular preference is given to compounds of the formula B2.

The compounds of formulas B1 to B3 are preferably selected from the group consisting of compounds of the following subformulas B1a, B2a, B2b and B2c:

Where

Alkyl ^* denotes an alkyl radical having 1 to 6 carbon atoms. The medium according to the invention particularly preferably comprises at least one compound of the formulas Bla and / or B2c.

8) LC mixture or LC medium further comprising at least one terphenyl compound of formula T:

[Formula T]

Where

R ⁵ and R ⁶ has one of the meanings described for R ¹ independently from each other, respectively,

는 각각 서로 독립적으로

를 나타내고, 여기서 L⁵는 F 또는 Cl, 바람직하게는 F를 나타내며, L⁶은 F, Cl, OCF₃, CF₃, CH₃, CH₂F 또는 CHF₂, 바람직하게는 F를 나타낸다.

Each independently of each other

Wherein L ⁵ represents F or Cl, preferably F, and L ⁶ represents F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F or CHF ₂ , preferably F.

The compound of formula T is preferably selected from the group consisting of the compounds of the following subformulas T1 to T25:

Where

R represents a straight chain alkyl or alkoxy radical having 1 to 7 carbon atoms, R ^* represents a straight chain alkenyl radical having 2 to 7 carbon atoms, (O) represents an oxygen atom or a single bond, and m is The integer of 1-6 is shown.

R ^* is preferably CH ₂ = CH-, CH ₂ = CHCH ₂ CH _2- , CH ₃ -CH = CH-, CH ₃ -CH ₂ -CH = CH-, CH _3- (CH ₂ ) ₂ -CH = CH-, CH _3- (CH ₂ ) ₃ -CH = CH- or CH ₃ -CH = CH- (CH ₂ ) _2- .

R preferably denotes methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy or pentoxy.

The LC medium according to the invention preferably comprises terphenyls of the formula T and its preferred subformulases in an amount of from 2 to 50% by weight, in particular from 5 to 20% by weight.

Particular preference is given to compounds of the formulas T1, T2, T3 and T21. In these compounds, R preferably denotes alkyl having 1 to 5 carbon atoms, and also alkoxy.

Terphenyl is preferably used in the mixtures according to the invention when the Δn value of the mixture is at least 0.1. Preferred mixtures comprise 2 to 20% by weight of at least one terphenyl compound selected from the group consisting of formula T, preferably compounds T1 to T22.

9) LC mixture or LC medium further comprising at least one compound of the formulas O1 to O7:

Where

R ¹ and R ² have the meanings described above and preferably represent, independently of one another, straight chain alkyl having 1 to 6 carbon atoms or straight chain alkenyl having 2 to 6 carbon atoms.

Preferred media include one or more compounds selected from formulas O1, O3 and O4.

10) LC mixture or LC medium further comprising at least one compound of the formula FI, preferably in an amount of more than 3% by weight, in particular 5% by weight or more and very particularly preferably from 5 to 30% by weight:

[Formula FI]

Where

는

Is

R ⁹ represents H, CH ₃ , C ₂ H ₅ or nC ₃ H ₇ , (F) represents an optional fluorine substituent, q represents 1, 2 or 3, and R ⁷ represents R ¹ Has one of the meanings described.

Particularly preferred compounds of formula FI are selected from the group consisting of the compounds of the following subformulas FI1 to FI8:

Where

R ⁷ preferably represents straight chain alkyl and R ⁹ represents CH ₃ , C ₂ H ₅ or nC ₃ H ₇ .

Particular preference is given to compounds of the formulas FI1, FI2 and FI3.

11) LC mixture or LC medium further comprising one or more compounds containing tetrahydronaphthyl or naphthyl units, such as, for example, compounds selected from the group consisting of compounds of the formulas N1 to N10:

Where

R ¹⁰ and R ¹¹ each independently of one another have one of the meanings described for R ¹ and preferably represent straight chain alkyl or alkoxy having 1 to 6 carbon atoms or straight chain alkenyl having 2 to 6 carbon atoms , Z ¹ and Z ² are each independently of the other -C ₂ H _4- , -CH = CH-,-(CH ₂ ) ₄ -,-(CH ₂ ) ₃ O-, -O (CH ₂ ) _3- , -CH = CHCH ₂ CH _2- , -CH ₂ CH ₂ CH ₂ CH = CH-, -CH ₂ O-, OCH _2- , -COO-, -OCO-, -C ₂ F _4- , -CF = CF-, -CF = CH-, -CH = CF-, -CH ₂ -or a single bond.

12) LC mixture or LC medium further comprising at least one difluorodibenzochroman and / or chromman of the formula BC or CR, preferably in an amount of from 3 to 20% by weight, in particular from 3 to 15% by weight:

[Formula BC]

[Formula CR]

Where

R ¹¹ and R ¹² each have the above-mentioned meaning independently of each other, and c represents 0 or 1.

Particularly preferred compounds of formulas BC and CR are selected from the group consisting of compounds of the following subformulae BC1 to BC7 and CR1 to CR5:

Where

Alkyl and alkyl ^* each independently represent a straight chain alkyl radical having 1 to 6 carbon atoms, and alkenyl and alkenyl ^* each independently represent a straight chain alkenyl radical having 2 to 6 carbon atoms. Alkenyl and alkenyl ^* are preferably CH ₂ = CH-, CH ₂ = CHCH ₂ CH _2- , CH ₃ -CH = CH-, CH ₃ -CH ₂ -CH = CH-, CH _3- (CH ₂ ) ₂ -CH = CH-, CH _3- (CH ₂ ) ₃ -CH = CH- or CH ₃ -CH = CH- (CH ₂ ) _2- .

Very particular preference is given to mixtures comprising one, two or three compounds of the formula BC2.

13) LC mixture or LC medium further comprising at least one fluorinated phenanthrene or dibenzofuran of formula PH or BF

[Formula PH]

[Formula BF]

Where

R ¹¹ and R ¹² each independently have the meanings mentioned above, b represents 0 or 1, L represents F and r represents 1, 2 or 3.

Particularly preferred compounds of the formulas PH and BF are selected from the group consisting of the compounds of the following subformulas PH1, PH2, BF1 and BF2:

Where

R and R 'each independently represent a straight chain alkyl or alkoxy radical having 1 to 7 carbon atoms.

14) Compounds containing at least one alkenyl group, or at least one CH ₂ group containing at least one alkyl group further substituted by CH═CH and optionally by another group, in particular no mesogenic or liquid crystal compound Do not use LC mixture.

15) LC mixture comprising at least one compound selected from the group consisting of formula CY with a 1, formula PY with b 0 and formula LY with f 0, in a total concentration of 1 to 60%.

16) LC mixture comprising at least one compound selected from the group consisting of Formula CY with a = 2 and Formula PY with b = 1 with a total concentration of 1-60%.

17) LC mixture comprising a total concentration of 1 to 50% of at least one compound selected from the group consisting of Formula CY and Formula T, wherein a is 2 and R ¹ and R ² are alkyl or alkenyl groups.

18) LC mixture comprising one or more compounds selected from the group consisting of: ZK1, ZK2, ZK5, ZK6, DK1, DK2, DK4, DK5, B1 and T1 in a total concentration of 1 to 60%.

19) LC mixture comprising at least one compound of formula ZK1 and / or ZK2 at a total concentration of 1-40%.

20) LC mixture comprising at least one compound selected from the group consisting of formulas ZK3, ZK4, B2 and B3 at a total concentration of 1-70%.

21) LC mixture comprising at least one compound of formula FI at a total concentration of 1-25%.

22) LC medium in which the concentration of the polymerizable component or compound A) is at most 5%, preferably at most 1%, particularly preferably at most 0.5%, preferably at least 0.01%, particularly preferably at least 0.1%.

23) LC medium in which the concentration of liquid crystal component (LC mixture) or component B) is at least 95%, particularly preferably at least 99%.

24) LC medium containing no compounds containing terminal vinyloxy groups (-O-CH = CH ₂ ) except for the polymerizable compounds of component A).

25) PSA-VA display with a pretilt angle of preferably 85 ° or less, particularly preferably 80 ° or less.

The individual components of the preferred embodiments 1) to 21) of the LC mixture according to the invention are known or those skilled in the art can easily derive their preparations from the prior art based on standard methods described in the literature. Can be. Compounds corresponding to formula CY are described, for example, in EP-A-0 364 538. Compounds corresponding to formula ZK are described, for example, in DE-A-26 36 684 and DE-A-33 21 373.

The combination of the LC mixtures of the abovementioned preferred embodiments 1) to 21) with the polymerized compounds described above and below gives a low threshold voltage, low rotation while maintaining high clearing point and high HR value in the LC medium according to the invention. Viscosity and very good low temperature stability are achieved, in particular a low pretilt angle is set quickly in the PSA display. In particular, the LC media in PSA displays exhibit significantly shorter response times, in particular also gray-shaded response times when compared to prior art media.

The LC mixture has a nematic phase range at 20 ° C. of preferably at least 80 K, particularly preferably at least 100 K and a rotational viscosity of at most 250 mPa · s, preferably at most 200 mPa · s.

In the VA type display according to the invention, the molecules in the layer of the LC medium in the switched-off state have a homeotropic alignment or a vertical alignment (homeotropic) to the electrode surface. When voltage is applied to the electrode, LC molecules with a longitudinal molecular axis are rearranged parallel to the electrode surface.

The LC mixture according to the invention for use in VA type displays preferably has a negative dielectric anisotropy Δε at 20 ° C. and 1 kHz, preferably in the range of -0.5 to -10, especially -2.5 to -7.5.

The birefringence Δn in the LC mixture according to the invention for use in VA type displays is preferably less than 0.16, particularly preferably 0.06 to 0.14, especially 0.07 to 0.12.

The LC mixtures and LC media according to the invention may also further comprise further additives known to those skilled in the art and described in the literature, for example polymerization initiators, inhibitors, stabilizers, surface-active substances or chiral dopants. They are polymerizable or non-polymerizable. The polymerizable additive is classified as appropriately polymerizable component or component A). Non-polymerizable additives are appropriately classified as LC mixtures (host mixtures) or non-polymerizable components or component B).

The LC mixture and LC medium may comprise, for example, one or more chiral dopants, preferably selected from compounds from Table B below.

However, LC media having no chiral or optically active ingredients at all are generally preferred.

0-15% by weight, preferably one or more additives selected from the group comprising polychromatic dyes, nanoparticles, conductive salts, complex salts, and materials for improving dielectric anisotropy, viscosity and / or alignment on the nematic phase 0-10% by weight may be added to the LC medium. Suitable and preferred conductive salts are, for example, complex salts of ethyldimethyldodecylammonium 4-hexoxybenzoate, tetrabutylammonium tetraphenylborate or crown ethers (see, eg, Haller et al., Mol. Cryst. Liq. Cryst. 24 , 249-258 (1973). Materials of this type are, for example, DE-A-22 09 127, DE-A-22 40 864, DE-A-23 21 632, DE-A-23 38 281, DE-A-24 50 088, DE -A-26 37 430 and DE-A-28 53 728.

When producing a PSA display, the polymerizable compound is polymerized or crosslinked by in situ polymerization in the LC medium between the substrates of the LC display by application of a voltage (if the compound contains two or more polymerizable groups). This polymerization can be carried out in one step. In addition, in the first step, the polymerization is first performed by application of a voltage to generate a pretilt angle, and then, in the second step, the compounds not reacted in the first step are polymerized or crosslinked without applying a voltage. (Final hardening) is also possible.

Suitable and preferred polymerization methods are, for example, thermal polymerization or photopolymerization, preferably photopolymerization, in particular UV photopolymerization. If desired, one or more initiators may be added. Suitable polymerization conditions, and suitable types and amounts of initiators are known to those skilled in the art and are described in the literature. Glass-initiator suitable for radical polymerization is, for example, ^(® Irgacure) divalent commercially the available photoinitiator Cure 651, Irgacure 184, Irgacure 907, Irgacure 369, or Darocure (Darocure ^®) 1173 (Ciba AG (Ciba AG)). If an initiator is used, the proportion is preferably 0.001 to 5% by weight, particularly preferably 0.001 to 1% by weight. However, this polymerization can also be carried out without the addition of initiators. In a further preferred embodiment, the LC medium does not comprise a polymerization initiator.

In addition, the polymerizable component A) or LC medium may comprise one or more stabilizers to prevent unwanted spontaneous polymerization of the RMs, for example during storage or transportation. Suitable types and amounts of stabilizers are known to those skilled in the art and are described in the literature. For example, commercially available stabilizers of the Iganox family (Ciba-age) are particularly suitable. If a stabilizer is used, the proportion is preferably 10 to 10,000 ppm, particularly preferably 50 to 500 ppm, based on the total amount of RM or polymerizable component A).

The polymerizable compounds are also suitable for polymerizing without an initiator, which entails significant advantages such as low material costs and low contamination of the LC medium, in particular by possible residual amounts of initiator or degradation products thereof.

The LC medium according to the invention for use in PSA displays is preferably at most 5%, particularly preferably at most 1%, very particularly preferably at most 0.5% and preferably at least 0.01%, particularly preferably at least 0.1%. Polymerizable compounds, in particular polymerizable compounds of the formulas mentioned above and below.

Particular preference is given to LC media comprising one, two or three polymerizable compounds.

More preferred are achiral polymeric compounds and LC media in which the compounds of components A) and / or B) are selected only from the group consisting of achiral compounds.

The polymerizable component or component A) is at least one polymerizable compound containing one polymerizable group (mono-reactive) and at least one, preferably at least two polymerizable groups (2- or polyreactive) More preferred are LC media comprising polymerizable compounds.

More preferred are PSA displays and LC media in which the polymerizable component or component A) comprises only polymerizable compounds containing two polymerizable groups (direactive).

The polymerizable compounds can be added individually to the LC medium, but it is also possible to use mixtures comprising two or more polymerizable compounds according to the invention. A copolymer is formed upon polymerization of this mixture. The invention also relates to the polymerizable mixtures mentioned above and below. The polymerizable compound may be mesogenic or non-mesogenic. Particular preference is given to polymerizable mesogenic compounds, also known as reactive mesogens (RM).

Suitable and preferred RMs for use in LC media and PSA displays according to the invention are described below.

In a preferred embodiment of the invention, the polymerizable compound is selected from the general formula (I ^* ):

[Formula I ^* ]

R ^a -B ^1- (Z ^b -B ² ) _m -R ^b

Each radical in the formula has the following meanings:

R ^a and R ^b each independently represent P, P-Sp-, H, halogen, SF ₅ , NO ₂ , a carbon group or a hydrocarbon group, wherein at least one of the radicals R ^a and R ^b is P or P-Sp When it represents or contains a group and B ¹ and / or B ² contains a saturated carbon atom, R ^a and / or R ^b may also represent a spiro-connected radical to said saturated carbon atom,

P represents in each case the same or differently polymerizable groups,

Sp represents the same or different in each case a spacer group or a single bond,

B ¹ and B ² each independently represent an aromatic, heteroaromatic, cycloaliphatic or heterocyclic group having preferably 4 to 25 ring atoms, which may also contain fused rings and are mono-substituted by L or Can be substituted

L represents a P-Sp-, H, OH, CH ₂ OH, halogen, SF ₅ , NO ₂ , carbon atom or hydrocarbon group,

Z ^b is the same or different at each occurrence: -O-, -S-, -CO-, -CO-O-, -OCO-, -O-CO-O-, -OCH _2- , -CH ₂ O- , -SCH _2- , -CH ₂ S-, -CF ₂ O-, -OCF _2- , -CF ₂ S-, -SCF ₂ -,-(CH ₂ ) _n 1-, -CF ₂ CH ₂ -,- CH ₂ CF ₂ -,-(CF ₂ ) _n 1-, -CH = CH-, -CF = CF-, -C≡C-, -CH = CH-COO-, -OCO-CH = CH-, CR ⁰ R ⁰⁰ or a single bond,

R ⁰ and R ⁰⁰ each independently represent H or alkyl having 1 to 12 carbon atoms,

m represents 0, 1, 2, 3 or 4,

n1 represents 1, 2, 3 or 4.

Particular preference is given to compounds of the formula I ^* having the following meanings:

R ^a and R ^b are each independently of each other P, P-Sp-, H, F, Cl, Br, I, -CN, -NO ₂ , -NCO, -NCS, -OCN, -SCN, SF ₅ , or 1 to 25 denotes a straight-chain or branched-chain alkyl having carbon atoms in which at least one further non-adjacent CH ₂ groups are each independently of one another by O and / or S atoms are -C in ways that are not directly connected to each other (R ⁰ ) = C (R ⁰⁰ )-, -C≡C-, -N (R ⁰⁰ )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O- May be replaced by CO—O— and also one or more H atoms may be replaced by F, Cl, Br, I, CN, P or P-Sp, wherein one or more of the radicals R ^a and R ^b are P Or represents or contains a P-Sp- group and when B ¹ and / or B ² contain a saturated carbon atom, R ^a and / or R ^b may also represent a spiro-connected radical to said saturated carbon atom There is,

B ¹ and B ² are each independently of each other 1,4-phenylene, naphthalene-1,4-diyl, naphthalene-2,6-diyl, phenanthrene-2,7-diyl, atracene-2, 7-diyl, fluorene-2,7-diyl, coumarin, flavone, wherein one or more CH groups in these groups may also be replaced by N, cyclohexane-1,4-diyl, wherein , And also one or more non-adjacent CH ₂ groups may be replaced by O and / or S), 1,4-cyclohexenylene, bicyclo [1.1.1] pentane-1,3-diyl, bi Cyclo [2.2.2] octane-1,4-diyl, spiro [3.3] heptane-2,6-diyl, piperidine-1,4-diyl, decahydronaphthalene-2,6-di 1, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, indene-2,5-diyl or octahydro-4,7-methanoinyne-2,5-diyl, wherein , All of these groups may be unsubstituted or mono- or polysubstituted by L),

L is P, P-Sp-, OH, CH ₂ OH, F, Cl, Br, I, -CN, -NO ₂ , -NCO, -NCS, -OCN, -SCN, -C (= O) N ( R ^x ) ₂ , -C (= 0) Y ¹ , -C (= 0) R ^x , -N (R ^x ) ₂ , optionally substituted silyl, optionally substituted aryl having 6 to 20 carbon atoms Or straight or branched chain alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 25 carbon atoms, wherein at least one H atom is F, Cl, P or Can be replaced by P-Sp-),

P and Sp have the meanings described above,

Y ¹ represents halogen,

R ^x is P, P-Sp-, H, halogen, straight chain, branched chain or cyclic alkyl having 1 to 25 carbon atoms (wherein at least one non-adjacent CH ₂ group is O and / or S atoms directly May be replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O— in an unconnected manner, and one or more H atoms may be F , Cl, P or P-Sp-), optionally substituted aryl or aryloxy group having 6 to 40 carbon atoms, or optionally substituted heteroaryl having 2 to 40 carbon atoms Or heteroaryloxy group.

Particularly preferred compounds of formula I ^* are selected from the following subformulaes M1 to M28:

Each radical in the formula has the following meanings:

P ¹ and P ² are each independently of one another preferably a polymerizable group having one of the meanings described above and below for P, particularly preferably acrylate, methacrylate, fluoroacrylate, oxetane, vinyloxy Or an epoxy group,

Sp ¹ and Sp ² are each independently of one another preferably a single bond or a spacer group having one of the meanings described above and below for Sp, particularly preferably-(CH ₂ ) _p1 -,-(CH ₂ ) _p1- O—, — (CH ₂ ) _p1 —CO—O— or — (CH ₂ ) _p1 —O—CO—O—, where p1 is an integer from 1 to 12 and the ring adjacent to one of the last mentioned groups. Is made through the O atom,

Radical P ¹ -Sp ¹ - and P ² -Sp ² - is one or more of, but can represent R ^aa, the radical P ¹ -Sp ¹ present here - and P ² -Sp ² - One or more of the indicated R ^aa Without,

R ^aa is a straight or branched chain alkyl having 1 to 25 carbon atoms (wherein also one or more non-adjacent CH ₂ groups are each independently of one another and C (R ^{0) in} such a way that the O and / or S atoms are not directly connected to each other ^. ) = C (R ⁰⁰ )-, -C≡C-, -N (R ⁰ )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O- May be replaced by CO—O—, and also one or more H atoms may be replaced by F, Cl, CN or P ¹ -Sp ¹ −, particularly preferably straight chain having 1 to 12 carbon atoms Or branched chain optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alcoholcarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, wherein alkenyl and alkynyl radicals Has at least two carbon atoms and branched radicals have at least three carbon atoms),

R ⁰ and R ⁰⁰ each independently of one another represent H or alkyl having 1 to 12 carbon atoms, identically or differently in each case,

R ^y and R ^z each independently represent H, F, CH ₃ or CF ₃ ,

Z ¹ represents —O—, —CO—, —C (R ^y R ^z ) — or —CF ₂ CF ₂ —,

Z ² and Z ³ are each independently -CO-O-, -O-CO-, -CH 2 O-, -OCH 2 each other _{-, -CF 2 O-, -OCF 2} - or - (CH _{2) n} -, Where n is 2, 3 or 4,

L is the same or different at each occurrence of F, Cl, CN or straight or branched chain optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl having 1 to 12 carbon atoms , Alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, preferably F,

L ′ and L ″ each independently represent H, F or Cl,

r represents 0, 1, 2, 3 or 4,

s represents 0, 1, 2 or 3,

t represents 0, 1 or 2,

x represents 0 or 1.

In a preferred embodiment, the LC medium comprises exactly one radical P-Sp or P ¹ -Sp ¹ or P ² -Sp ² , wherein Sp or Sp ¹ or Sp ² represents a single bond and exactly one radical P- Group consisting of a compound of formula I ^* or a subformulae thereof (“single spacer compound”) containing Sp or P ¹ -Sp ¹ or P ² -Sp ² (Sp or Sp ¹ or Sp ² is not a single bond) Preferably selected from only one or more RMs.

In a further preferred embodiment of the invention, the polymerizable compound is an optically active compound selected from chiral or formula II ^* :

Formula II ^* ]

(R ^* -(B ¹ -Z ^b ) _m ) _k -Q

Where

B ¹ , Z ^b and m each have the same or different meanings as defined in formula (I ^*) ,

R ^* has the same or different occurrences at each occurrence of one of the meanings described for Ra in Formula I ^* , wherein R ^* can be chiral or achiral,

Q represents a k-valent chiral group, optionally mono- or polysubstituted by L, as defined in Formula I ^* ,

k is 1, 2, 3, 4, 5 or 6,

Wherein said compound contains one or more radicals R ^* or L, which represent or contain a P or P-Sp- group as defined above.

Particularly preferred compounds of formula II ^* contain monovalent Q groups of formula III ^* :

[Formula III ^* ]

Where

L and r in each case have the same or different meanings described above,

A ^* and B ^* each independently represent fused benzene, cyclohexane or cyclohexene,

t represents 0, 1 or 2, identically or differently in each case,

u represents 0, 1 or 2, identically or differently, in each case.

Particular preference is given to groups of the formula III ^* in which u represents 1.

Another preferred compound of Formula II ^* contains a monovalent Q group or one or more R ^* groups of Formula IV ^* :

[Formula IV ^* ]

Where

Q ¹ represents an alkylene or alkyleneoxy having 1 to 9 carbon atoms, or a single bond,

Q ² represents optionally fluorinated alkyl or alkoxy having 1 to 10 carbon atoms, wherein also one or two non-adjacent CH ₂ groups are -O in such a way that the O and / or S atoms are not directly connected to each other. Replaced by-, -S-, -CH = CH-, -CO-, -OCO-, -COO-, -O-COO-, -S-CO-, -CO-S- or -C≡C- Can be,

Q ³ represents alkyl or alkoxy as defined for F, Cl, CN, or Q ² , but is different from Q ² .

Preferred groups of formula IV ^* are, for example, 2-butyl (= 1-methylpropyl), 2-methylbutyl, 2-methylpentyl, 3-methylpentyl, 2-ethylhexyl, 2-propylpentyl, especially 2-methyl Butyl, 2-methylbutoxy, 2-methylpentoxy, 3-methylpentoxy, 2-ethylhexoxy, 1-methylhexoxy, 2-octyloxy, 2-oxa-3-methylbutyl, 3-oxa- 4-methylpentyl, 4-methylhexyl, 2-hexyl, 2-octyl, 2-nonyl, 2-decyl, 2-dodecyl, 6-methoxyoctoxy, 6-methyloctoxy, 6-methyloctanoyloxy , 5-methylheptyloxycarbonyl, 2-methylbutyryloxy, 3-methylvaleroyloxy, 4-methylhexanoyloxy, 2-chloropropionyloxy, 2-chloro-3-methylbutyryloxy, 2 -Chloro-4-methylvaleryloxy, 2-chloro-3-methylvaleryloxy, 2-methyl-3-oxa-pentyl, 2-methyl-3-oxahexyl, 1-methoxypropyl-2-oxy, 1-ethoxypropyl-2-oxy, 1-propoxypropyl-2-oxy, 1-butoxypropyl-2-oxy, 2-fluorooctyloxy, 2-fluorodecyloxy, 1,1,1 -Triple By oro-2-octyloxy, 1,1,1-trifluoro-2-octyl, 2-fluoro-a-methyl-octyloxy.

Another preferred compound of Formula (II ^* ) contains a divalent Q group of Formula (V ^* ):

[Formula V ^* ]

Where

L, r, t, A ^* and B ^* have the meanings described above.

Another preferred compound of Formula (II ^* ) contains a divalent Q group selected from:

Where

Phe represents phenyl optionally mono- or polysubstituted by L and R ^x represents F, or optionally fluorinated alkyl having 1 to 4 carbon atoms.

Suitable chiral RMs are disclosed, for example, in GB 2 314 839 A, US 6,511,719, US 7,223,450, WO 02/34739 A1, US 7,041,345, US 7,060,331 or US 7,318,950. Suitable RMs containing binaphthyl groups are disclosed, for example, in US Pat. No. 6,818,261, US Pat. No. 6,916,940, US 7,318,950 and US 7,223,450.

The chiral structural elements described above and below, and polymerizable or polymerized compounds containing such chiral structural elements, can be used as optically active forms, i.e. pure enantiomers or any desired mixtures of two enantiomers, or alternatively as racemates. Can be. The use of racemates is preferred. The use of racemates has some advantages over the use of pure enantiomers, for example, in much lower synthesis complexity and lower material costs. The use of racemates also makes it possible to prevent unwanted kinks of LC molecules in the LC display.

Particularly preferred compounds of formula II ^* are selected from compounds of subformula II ^* 1 to II ^* 11:

Where

L, P, Sp, m, r and t have the meanings described above,

Z and A in each occurrence have the same or different meanings as described for Z ¹ or A ¹ , respectively,

t1 represents 0 or 1 in each case the same or differently.

The term "carbon group" contains no additional atoms at all (eg -C≡C-) or optionally one or more such as, for example, N, O, S, P, Si, Se, As, Te or Ge Monovalent or polyvalent organic groups containing additional atoms (eg, carbonyl, etc.) are shown. The term "hydrocarbon group" denotes a carbon group which further contains one or more H atoms and optionally one or more heteroatoms such as, for example, N, O, S, P, Si, Se, As, Te or Ge.

"Halogen" refers to F, Cl, Br or I.

Carbon or hydrocarbon groups can be saturated or unsaturated groups. Unsaturated groups are, for example, aryl, alkenyl or alkynyl groups. Carbon or hydrocarbon radicals having three or more carbon atoms may be straight chain, branched and / or cyclic, and may also have spiro bonds or condensed rings.

The terms "alkyl", "aryl", "heteroaryl" and the like also include polyvalent groups such as alkylene, arylene, heteroarylene and the like.

The term "aryl" refers to an aromatic carbon group or a group derived therefrom. The term "heteroaryl" refers to "aryl" as defined above, containing one or more heteroatoms.

Preferred carbon and hydrocarbon groups are optionally substituted alkyl, alkenyl, alkynyl, alkoxy, alkylcarbonyl, alkoxycarbons having 1 to 40, preferably 1 to 25, particularly preferably 1 to 18 carbon atoms Neyl, alkylcarbonyloxy and alkoxycarbonyloxy; Optionally substituted aryl or aryloxy having 6 to 40, preferably 6 to 25 carbon atoms; Or optionally substituted alkylaryl, arylalkyl, alkylaryloxy, arylalkyloxy, arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy and aryl having 6 to 40, preferably 6 to 25 carbon atoms Oxycarbonyloxy.

Another preferred carbon and hydrocarbon group is C ₁ -C ₄₀ alkyl, C ₂ -C ₄₀ alkenyl, C ₂ -C ₄₀ alkynyl, C ₃ -C ₄₀ allyl, C ₄ -C ₄₀ alkyldienyl, C ₄ -C ₄₀ polyenyl, C ₆ -C ₄₀ aryl, C ₆ -C ₄₀ alkylaryl, C ₆ -C ₄₀ arylalkyl, C ₆ -C ₄₀ alkylaryloxy, C ₆ -C ₄₀ arylalkyloxy, C ₂ -C ₄₀ heteroaryl, C ₄ -C ₄₀ cycloalkyl, C ₄ -C ₄₀ cycloalkenyl and the like. Among these, C ₁ -C ₂₂ alkyl, C ₂ -C ₂₂ alkenyl, C ₂ -C ₂₂ alkynyl, C ₃ -C ₂₂ allyl, C ₄ -C ₂₂ alkyldienyl, C ₆ -C ₁₂ aryl, C Particular preference is given to _6- C ₂₀ arylalkyl and C ₂ -C ₂₀ heteroaryl.

Another preferred carbon and hydrocarbon group is unsubstituted or mono- or polysubstituted by F, Cl, Br, I or CN and one or more non-adjacent CH ₂ groups are each independently of one another and the O and / or S atoms are directly -C (R ^x ) = C (R ^x )-, -C≡C-, -N (R ^x )-, -O-, -S-, -CO-, -CO-O -Straight, branched or cyclic alkyl radicals having 1 to 40, preferably 1 to 25 carbon atoms, which may be replaced by -O-CO-, -O-CO-O-.

R ^x is preferably H; halogen; In addition, one or more non-adjacent carbon atoms may be replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O—, and one or more H Straight, branched or cyclic alkyl chains having 1 to 25 carbon atoms, wherein the atoms may be replaced by fluorine; Optionally substituted aryl or aryloxy groups having 6 to 40 carbon atoms; Or an optionally substituted heteroaryl or heteroaryloxy group having 2 to 40 carbon atoms.

Preferred alkyl groups are, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, cyclopentyl, n -Hexyl, cyclohexyl, 2-ethylhexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, dodecaneyl, trifluoromethyl , Perfluoro-n-butyl, 2,2,2-trifluoroethyl, perfluorooctyl, perfluorohexyl and the like.

Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl and the like.

Preferred alkynyl groups are, for example, ethynyl, propynyl, butyryl, pentynyl, hexynyl, octinyl and the like.

Preferred alkoxy groups are, for example, methoxy, ethoxy, 2-methoxy-ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy , 2-methylbutoxy, n-pentoxy, n-hexoxy, n-heptyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, n-undecyloxy, n-dodecyloxy and the like to be.

Preferred amino groups are, for example, dimethylamino, methylamino, methylphenylamino, phenylamino and the like.

Aryl and heteroaryl groups may be monocyclic or polycyclic, ie they may contain one ring (eg phenyl) or may contain two or more rings and they may also be fused (eg naph Yl) may be covalently bonded (eg, biphenyl) or may contain a combination of fused and combined rings. Heteroaryl groups preferably contain one or more heteroatoms selected from O, N, S and Se.

Especially preferred of these are monocyclic, bicyclic or tricyclic aryl groups having 6 to 25 carbon atoms and monocyclic, bicyclic or tricyclic heteroaryl groups having 2 to 25 carbon atoms, which optionally contain fused rings And optionally substituted. Further preferred are 5-, 6- or 7-membered aryl and heteroaryl groups in which one or more CH groups can be replaced by N, S or O in such a way that no O atoms and / or S atoms are directly connected to each other.

Preferred aryl groups are, for example, phenyl, biphenyl, terphenyl, [1,1 ': 3', 1 "] terphenyl-2'-yl, naphthyl, anthracene, binaphthyl, phenanthrene, pyrene, di Hydropyrene, chrysene, perylene, tetracene, pentacene, benzopyrene, fluorene, indene, indenofluorene, spirobifluorene and the like.

Preferred heteroaryl groups are, for example, 5-membered rings such as pyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, furan, thiophene, selenophene, oxa Sol, isoxazole, 1,2-thiazole, 1,3-thiazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole; 6-membered rings such as pyridine, pyridazine, pyrimidine, pyrazine, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, 1,2,4,5-tetra Gin, 1,2,3,4-tetraazine, 1,2,3,5-tetraazine; Or condensation groups such as indole, isoindole, indolizine, indazole, benzimidazole, benzotriazole, purine, naftimidazole, phenanthrimidazole, pyridimidazole, pyrazineimidazole, quinoxalineimidazole , Benzoxazole, naphtoxazole, antrazole, phenanthroxazole, isoxazole, benzothiazole, benzofuran, isobenzofuran, dibenzofuran, quinoline, isoquinoline, putridine, benzo-5,6 -Quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, benzoisoquinoline, acridine, phenothiazine, phenoxazine, benzopyridazine, benzopyrimidine, quinoxaline, phenazine, naphthyridine , Azacarbazole, benzocarboline, phenanthridine, phenanthroline, thieno [2,3b] thiophene, thieno [3,2b] thiophene, dithienothiophene, isobenzothiophene, dibenzothione Offen, benzothiadiazothiophene; Or a combination of these groups. Heteroaryl groups may also be substituted by alkyl, alkoxy, thioalkyl, fluorine, fluoroalkyl or further aryl or heteroaryl groups.

(Non-aromatic) alicyclic and heterocyclic groups include both saturated rings containing only single bonds, and also partially unsaturated rings, which may contain multiple bonds. The heterocyclic ring preferably contains one or more heteroatoms selected from Si, O, N, S and Se.

(Non-aromatic) alicyclic and heterocyclic groups may be monocyclic, ie contain only one ring (eg cyclohexane), or polycyclic, ie contain multiple rings (eg decahydro Naphthalene or bicyclooctane). Especially preferred among these are saturated groups. More preferred are monocyclic, bicyclic or tricyclic groups with 3 to 25 carbon atoms, optionally containing fused rings and optionally substituted. In addition, one or more carbon atoms may be replaced by Si and / or one or more CH groups may be replaced by N and / or one or more non-adjacent CH ₂ groups may be replaced by -O- and / or -S-. Even more preferred are 5-, 6-, 7- or 8-membered carbocyclic groups.

Preferred alicyclic and heterocyclic groups are, for example, five-membered groups such as cyclopentane, tetrahydrofuran, tetrahydrothiofuran, pyrrolidine; 6 membered groups such as cyclohexane, silaneine, cyclohexene, tetrahydropyran, tetrahydrothiopyran, 1,3-dioxane, 1,3-dithiane, piperidine; 7 membered groups such as cycloheptane; And fusion groups such as tetrahydronaphthalene, decahydronaphthalene, indene, bicyclo [1.1.1] pentane-1,3-diyl, bicyclo [2.2.2] octane-1,4-diyl, spiro [3.3] heptane-2,6-diyl, octahydro-4,7-methanoydine-2,5-diyl.

Preferred substituents are, for example, solubility-promoting groups such as alkyl or alkoxy; Electron-drawing groups such as fluorine, nitro or nitrile; Or substituents for increasing the glass transition temperature (Tg) of the polymer, in particular bulk groups such as t-butyl or optionally substituted aryl groups.

Preferred substituents, also referred to above and hereinafter as "L", include, for example, F, Cl, Br, I, -CN, -NO ₂ , -NCO, -NCS, -OCN, -SCN, -C ( = O) N (R ^x ) ₂ , -C (= 0) Y ¹ , -C (= 0) R ^x , -N (R ^x ) ₂ , wherein R ^x has the meanings described above and Y ¹ is Halogen, optionally substituted silyl or aryl having 6 to 40, preferably 6 to 20 carbon atoms, and straight or branched chain alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl having 1 to 25 carbon atoms , Alkylcarbonyloxy or alkoxycarbonyloxy, wherein one or more H atoms are optionally replaced by F or Cl.

"Substituted silyl or aryl" is preferably halogen, -CN, R ^O , -OR ^O , -CO-R ^O , -CO-OR ^O , -O-CO-R ^O , or -O-CO-OR Meaning substituted with ^O (wherein R ^O has the meaning described above).

Particularly preferred substituents L are, for example, F, Cl, CN, NO ₂ , CH ₃ , C ₂ H ₅ , OCH ₃ , OC ₂ H ₅ , COCH ₃ , COC ₂ H ₅ , COOCH ₃ , COOC ₂ H ₅ , CF ₃ , OCF ₃ , OCHF ₂ , OC ₂ F ₅ , and also phenyl.

는 바람직하게는

이며, 여기서 L은 상기 기재된 의미 중 하나를 갖는다.

Is preferably

Wherein L has one of the meanings described above.

The polymerizable group P is a group suitable for free-radical or ionic chain polymerization, polymerisation reactions such as polyaddition or polycondensation, or polymer-like reactions such as addition or condensation into the polymer backbone. Particular preference is given to groups for chain polymerization, in particular those containing C═C double bonds or C≡C triple bonds and groups suitable for polymerization by ring opening, such as oxetane or epoxy groups.

, CH₂=CW²-(O)_k3-, CW¹=CH-CO-(O)_k3-, CW¹=CH-CO-NH-, CH₂=CW¹-CO-NH-, CH₃-CH=CH-O-, (CH₂=CH)₂CH-OCO-, (CH₂=CH-CH₂)₂CH-OCO-, (CH₂=CH)₂CH-O-, (CH₂=CH-CH₂)₂N-, (CH₂=CH-CH₂)₂N-CO-, HO-CW²W³-, HS-CW²W³-, HW²N-, HO-CW²W³-NH-, CH₂=CW¹-CO-NH-, CH₂=CH-(COO)_k1-Phe-(O)_k2-, CH₂=CH-(CO)_k1-Phe-(O)_k2-, Phe-CH=CH-, HOOC-, OCN- 및 W⁴W⁵W⁶Si- 중에서 선택되고, 여기서 W¹은 H, F, Cl, CN, CF₃, 페닐 또는 1 내지 5개의 탄소 원자를 갖는 알킬, 특히 H, F, Cl 또는 CH₃를 나타내고, W² 및 W³은 각각 서로 독립적으로 H 또는 1 내지 5개의 탄소 원자를 갖는 알킬, 특히 H, 메틸, 에틸 또는 n-프로필을 나타내고, W⁴, W⁵ 및 W⁶은 각각 서로 독립적으로 Cl, 1 내지 5개의 탄소 원자를 갖는 옥사알킬 또는 옥사카보닐알킬을 나타내고, W⁷ 및 W⁸은 각각 서로 독립적으로 H, Cl 또는 1 내지 5개의 탄소 원자를 갖는 알킬이고, Phe는 P-Sp-와는 다른 상기 정의된 바와 같은 하나 이상의 L 라디칼에 의해 임의적으로 치환된 1,4-페닐렌을 나타내고, k₁, k₂ 및 k₃은 각각 서로 독립적으로 0 또는 1이고, k₃은 바람직하게는 1을 나타낸다.Preferred P groups are CH ₂ = CW ¹ -COO-, CH ₂ = CW ¹ -CO-,

, CH ₂ = CW ^2- (O) _k3- , CW ¹ = CH-CO- (O) _k3- , CW ¹ = CH-CO-NH-, CH ₂ = CW ¹ -CO-NH-, CH _3- CH = CH-O-, (CH ₂ = CH) ₂ CH-OCO-, (CH ₂ = CH-CH ₂ ) ₂ CH-OCO-, (CH ₂ = CH) ₂ CH-O-, (CH ₂ = CH-CH ₂ ) ₂ N-, (CH ₂ = CH-CH ₂ ) ₂ N-CO-, HO-CW ² W ^3- , HS-CW ² W ^3- , HW ² N-, HO-CW ² W ^{_{3 -NH-, CH 2 = CW 1}} -CO-NH-, CH 2 = CH- (COO) k1 -Phe- (O) k2 -, CH 2 = CH- (CO) k1 -Phe- (O) k2 -, Phe-CH = CH-, HOOC-, OCN- and W ⁴ W ⁵ W ⁶ Si-, wherein W ¹ is H, F, Cl, CN, CF ₃ , phenyl or 1 to 5 carbon atoms Alkyl having, in particular H, F, Cl or CH ₃ , W ² And W ³ each independently represent H or alkyl having 1 to 5 carbon atoms, in particular H, methyl, ethyl or n-propyl, W ⁴ , W ⁵ And W ⁶ each independently represent Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 carbon atoms, and W ⁷ and W ⁸ each independently represent H, Cl or 1 to 5 carbon atoms Alkyl, Phe represents 1,4-phenylene optionally substituted by one or more L radicals as defined above other than P-Sp-, k ₁ , k ₂ And k ₃ are each independently 0 or 1, and k ₃ preferably represents 1.

및

이다.Particularly preferred P groups are CH ₂ = CW ¹ -COO-, in particular CH ₂ = CH-COO-, CH ₂ = C (CH ₃ ) -COO-, CH ₂ = CF-COO-, CH ₂ = CH-O-, (CH ₂ = CH) ₂ CH-OCO-, (CH ₂ = CH) ₂ CH-O-,

And

to be.

Very particularly preferred P groups are vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxides, in particular acrylates and methacrylates.

Preferred spacer group Sp is selected from formula Sp'-X 'such that radical P-Sp- corresponds to formula P-Sp'-X'-, wherein

Sp 'represents alkylene having 1 to 20, preferably 1 to 12 carbon atoms, which is optionally mono- or polysubstituted by F, Cl, Br, I or CN and also at least one non- adjacent CH ₂ groups are each independently selected from O and / or S atoms in ways that are not directly connected to each other -O-, -S-, -NH-, -NR ^O together -, -SiR R ^{O OO} -, -CO-, -COO-, -OCO-, -OCO-O-, -S-CO-, -CO-S-, -NR ^O0 -CO-O-, -O-CO-NR ^O0- , -NR ^O0 -CO- NR ^0-- , -CH = CH- or -C≡C- can be replaced,

X 'is -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR ^O0- , -NR ^O0 -CO-, -NR ^O0 -CO-NR _{^{O0 -, -OCH 2 -, -CH}} 2 O-, -SCH 2 -, -CH 2 S-, -CF 2 O-, -OCF 2 -, -CF 2 S-, -SCF 2 -, -CF 2 CH _2- , -CH ₂ CF _2- , -CF ₂ CF _2- , -CH = N-, -N = CH-, -N = N-, -CH = CR ^O- , -CY ² = CY ^3- , -C≡C-, -CH = CH-COO-, -OCO-CH = CH- or a single bond,

R ^O0 and R ^O0O each independently represent H or alkyl having 1 to 12 carbon atoms,

Y ² and Y ³ each independently represent H, F, Cl or CN.

X 'is preferably -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR ^O- , -NR ^O -CO-, -NR ^O- CO-NR ^O -or a single bond.

Typical spacer groups Sp ′ are, for example, — (CH ₂ ) _{p 1} —, — (CH ₂ CH ₂ O) _{q 1} —, —CH ₂ CH ₂ —, —CH ₂ CH ₂ —S—CH ₂ CH ₂ —, _{-CH 2 CH 2 -NH-CH 2} CH 2 - or ^{- (SiR O0 R O0O -O)} p1 - , and (wherein, p1 is an integer from 1 to 12, q1 is an integer from 1 to 3, R and R ^{O0 O0O} has the meaning described above).

A particularly preferred group -X'-Sp'- is _{- (CH 2) p1 -,} -O- (CH 2) p1 -, -OCO- (CH 2) p1 -, -OCOO- (CH 2) p1 - a.

Particularly preferred groups Sp 'are, in each case, straight chain ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, Ethyleneoxyethylene, methyleneoxybutylene, ethylenethioethylene, ethylene-N-methyliminoethylene, 1-methylalkylene, ethenylene, propenylene and butenylene.

In a further preferred embodiment of the invention, P-Sp- represents a radical containing at least two polymerizable groups (multifunctional polymerizable radicals). Suitable radicals of this type and polymerizable compounds containing them and processes for their preparation are disclosed, for example, in US 7,060,200 B1 or US 2006/0172090 A1. Especially preferred are polyfunctional polymerizable radicals P-Sp selected from the formulas I ^* a to I ^* m:

Where

Alkyl is a single bond, or straight or branched chain alkylene having 1 to 12 carbon atoms, wherein one or more non-adjacent CH ₂ groups are each independently of one another in such a way that no O and / or S atoms are directly connected to each other; C (R ⁰⁰ ) = C (R ⁰⁰⁰ )-, -C≡C-, -N (R ⁰⁰ )-, -O-, -S-, -CO-, -CO-O-, -O-CO- , -O-CO-O-, and also one or more H atoms can be replaced by F, Cl or CN, wherein R ⁰⁰ and R ⁰⁰⁰ have the meanings mentioned above,

aa and bb each independently represent 0, 1, 2, 3, 4, 5 or 6,

X has one of the meanings described for X ',

P ¹ To P ⁵ each independently of one another have one of the meanings described for P.

More preferred are compounds of formula I ^* or a subformulae thereof, wherein B ¹ and / or B ² represent at least partially substituted radicals, preferably cyclohexylene, wherein R ^a and / or R ^b represent P- or denotes a P-sp sp ³ of the radicals B ¹ or B ² - is connected to the hybrid carbon atoms, such sp ³ - hybrid carbon atoms is preferably the same as the same sp ³ attached to a carbon atom radicals R ^a or R ^b means a radical P (or P ^1/2), or P-Sp- having (or P ¹ -Sp ¹ - or P ² -Sp ² -) is also contained as a single substituent.

Particularly preferred compounds contain structural elements of formula (I ^* n):

[Formula I ^* n]

-C ^sp3 ((CH ₂ ) _aa P ¹ ) ((CH ₂ ) _bb P ² )

Where

C ^sp3 represents an sp ³ -mixed carbon atom in the radical B ¹ or B ² , and P ¹ , P ² , aa and bb have the meanings described above.

Polymerizable compounds and RMs are known to those skilled in the art and are described in standard workbooks of organic chemistry, such as, for example, in Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], Thieme-Verlag, Stuttgart. It can be made similar to the process described. Further synthetic methods are disclosed in the documents cited above and below. In the simplest case, the synthesis of such RMs, for example 2,6-dihydroxynaphthalene or 4,4'-dihydroxybiphenyl, for example in the presence of a dehydrating agent such as DCC (dicyclohexylcarbodiimide) This is accomplished by esterification or etherification with the corresponding acid, acid derivative or halogenated compound containing P group, such as meth) acryloyl chloride or (meth) acrylic acid.

The LC media which can be used according to the invention are prepared in a conventional manner, for example by mixing one or more of the abovementioned compounds with one or more polymerizable compounds as defined above and optionally further liquid crystal compounds and / or additives. Are manufactured. In general, the desired amount of the component used in smaller amounts is advantageously dissolved in the main component at elevated temperatures. It is also possible to mix solutions of the components in organic solvents such as acetone, chloroform or methanol and then remove the solvent again, for example by distillation, after complete mixing. The invention also relates to a process for the preparation of an LC medium according to the invention.

It is natural to those skilled in the art that the LC medium according to the invention may comprise a compound, for example H, N, O, Cl, F replaced by the corresponding isotope.

The structure of the LC display according to the invention corresponds to the conventional geometry for PSA displays as described in the prior art cited above. Geometries without protrusions, in particular also geometries, in which the electrodes on the color filter face are not structured and only the electrodes on the TFT face have slits. Particularly suitable and preferred electrode structures for PS-VA displays are described, for example, in US 2006/0066793 A1.

The LC mixtures and LC media according to the invention are in principle suitable for any type of PS or PSA displays, especially those based on LC dielectrics of negative dielectric anisotropy, particularly preferably PSA-VA, PSA-IPS or PS-FFS. . However, those skilled in the art will also appreciate that suitable LC mixtures and LC media according to the present invention without further steps may, for example, be used as substrates, alignment layers, electrodes in terms of the display and basic structure mentioned above or in terms of the nature, arrangement or structure of the individual components used. , Addressing elements, halos, polarizers, color filters, optional compensation films, etc., may be used in other displays of other PS or PSA type, such as PS-TN or PS-OCB displays.

The following examples illustrate the invention without limitation. However, those skilled in the art will appreciate the preferred mixture concepts having the compounds used preferably and their individual concentrations and combinations with each other. In addition, the following examples illustrate the properties and combinations of properties that may be used.

The following abbreviations are used:

(n, m, z are each independently 1, 2, 3, 4, 5 or 6)

TABLE A

In a preferred embodiment of the invention, the LC medium according to the invention comprises at least one compound selected from the group consisting of the compounds of Table A above.

Table B below shows the possible chiral dopants that can be added to the LC medium according to the invention.

TABLE B

The LC medium preferably comprises 0 to 10% by weight, in particular 0.01 to 5% by weight, particularly preferably 0.1 to 3% by weight of dopant. The LC medium preferably comprises at least one dopant selected from the group consisting of the compounds of Table B above.

Table C below shows the possible stabilizers that can be added to the LC medium according to the invention. (Where n represents an integer of 1 to 12)

TABLE C

The LC medium preferably comprises 0 to 10% by weight, in particular 1 to 5% by weight, particularly preferably 1 to 1% by weight of stabilizer. The LC medium preferably comprises at least one stabilizer selected from the group consisting of the compounds of Table C above.

Table D below shows exemplary compounds which can be used in the LC medium according to the invention, preferably as reactive mesogenic compounds.

TABLE D

In a preferred embodiment of the invention, said mesogenic medium comprises at least one compound selected from the group of compounds from Table D above.

In addition, the following abbreviations and symbols are used:

V ₀ represents the capacitive threshold voltage [V] at 20 ° C.

n _e represents the extraordinary refractive index at 20 ° C. and 589 nm.

n ₀ represents the normal refractive index at 20 ° C. and 589 nm.

Δn shows optical anisotropy at 20 ° C. and 589 nm.

ε _을 represents the dielectric susceptibility perpendicular to the director at 20 ° C. and 1 kHz.

ε _∥ shows the dielectric sensitivity parallel to the director at 20 ° C. and 1 kHz.

Δε represents dielectric anisotropy at 20 ° C and 1 kHz.

cl.p., T (N, I) represents clear point [degreeC].

γ ₁ represents the rotational viscosity [mPa.s] at 20 ° C.

K ₁ represents the elastic constant at 20 ° C., “splay” strain [pN].

K ₂ represents the elastic constant at 20 ° C., the “twist” strain [pN].

K ₃ represents the elastic constant at 20 ° C., “bend” strain [pN].

LTS represents the low temperature stability (phase) measured in the test cell.

HR ₂₀ represents the voltage holding ratio [%] at 20 ° C.

HR ₁₀₀ represents the voltage holding ratio [%] at 100 ° C.

Unless otherwise explicitly indicated, all concentrations and% values herein are expressed in weight percent (except for HR, contrast and permeability), and corresponding mixtures comprising all solid or liquid crystalline components in total without solvent. It is about.

Unless otherwise explicitly indicated, all temperature values described herein, such as melting point T (C, N), transition temperature from Smectic (S) to nematic (N) and T.S. T (N, I) is expressed in degrees Celsius (° C.). m.p. represents the melting point and cl.p. represents the clearing point. In addition, C is a crystalline state, N is a nematic phase, S is a smectic phase and I is an isotropic phase. The data between these symbols represents the transition temperature.

Unless otherwise explicitly indicated in each case, all properties are described in "Merck Liquid Crystals, Physical Properties of Liquid Crystals", Status Nov. 1997, Merck KGaA, Germany], a temperature of 20 ° C. is applied, Δn is measured at 589 nm and Δε is measured at 1 kHz.

For the present invention, the term “threshold voltage” relates to a capacitive threshold V ₀ , also referred to as a Freedericks threshold, unless explicitly stated otherwise. In an embodiment it may generally be represented by an optical threshold V ₁₀ for 10% relative contrast.

The display used to measure the capacitive threshold voltage consists of two planar-parallel glass outer plates separated by 20 μm, each of which comprises an electrode layer on the inner plate inner surface, which causes the homeotropic edge alignment of the liquid crystal molecules; It has a top non-rubbed polyimide alignment layer.

The display or test cell used to measure the tilt angle consists of two flat-parallel glass outer plates separated by 4 μm, each of which has an electrode layer on the outer plate inner surface and a polyimide alignment layer on top. The two polyimide layers rubbed antiparallel to each other and cause homeotropic edge alignment of the liquid crystal molecules.

The polymerizable compound is polymerized in the display or test cell by UV irradiation for a predetermined time while simultaneously applying a voltage (typically 10 V to 30 V alternating current, 1 kHz) to the display. In the examples, unless otherwise explicitly indicated, a 28 mW / cm 2 mercury vapor lamp was used and the intensity was measured using a standard UV meter (Ushio UNI meter) equipped with a 365 nm band-pass filter. .

Tilt angles were measured by a rotation determination experiment (Autronic-Melchers TBA-105). Here, small values (ie, angles with large deviations from 90 °) correspond to large tilts.

The VHR value is measured as follows: 0.3% of the polymerizable monomeric compound is added to the LC host mixture and the resulting mixture is rubbed at a 90 ° TN-VHR test cell, TN-polyimide alignment layer, layer The thickness d is introduced at about 4 μm). HR values are measured 5 min at 100 ° C. before and after UV exposure (sunlight test) for 2 h in 1 V, 60 Hz, 64 μs pulses (Measuring Instrument: Otronic-Melchers VHRM-105).

Example  One

The nematic LC mixture N1 according to the invention comprising 4% of the compound of formula I (CPGP-4-3) was formulated as follows:

Example  2

The nematic LC mixture N2 according to the invention comprising 5% of the compound of formula I (CPYP-3-2) was formulated as follows:

Example  3

The nematic LC mixture N3 according to the invention comprising 7% of the compound of formula I (CCOC-3-3, CCOC-4-3, CBC-33F) is formulated as follows:

Example  4

The nematic LC mixture N4 according to the invention comprising 4% of the compounds of formula I (CCOC-3-3, CCOC-4-3) is formulated as follows:

Comparative example  One

The nematic LC mixture C1 was formulated as follows:

Example  5

In each case, 0.3% of RM1 (biphenyl 4,4'-dimethacrylate) was added to LC mixtures N1 to N4 and comparative mixture C1 according to the invention:

[Formula RM1]

The resulting LC medium was each introduced into a VA e / o test cell as described above. RM was polymerized by irradiating the cell with UV light (365 nm) with an intensity of 50 mW / cm 2 for various periods while applying a 24 V (AC) voltage.

To determine the rate of polymerization, the HPLC method was used to determine the residual content of non-polymerized RM1 (% by weight) in the test cell after various exposure times. To this end, each mixture in the test cell was polymerized under the indicated conditions. The mixture was then washed out of the test cell using MEK (methyl ethyl ketone) and measured. The results are summarized in Table 1 below.

As can be seen from Table 1, only a small amount of non-polymerized RM1 was still present in the cell for the LC mixtures N1 to N4 according to the invention, after only a short exposure time, but for the comparative mixture C1 each was identical. There was still a significant amount of non-polymerized RM1 after the exposure time. From this it can be concluded that the polymerization rate of RM1 in the LC mixtures N1 to N4 according to the invention is considerably higher.

Thus, for example after 6 minutes of exposure time the LC medium N1 + RM1 according to the invention had a 30% lower RM residual content than the comparative medium C1 + RM1. In the case of LC media N2 + RM1, N3 + RM1 and N4 + RM1 according to the invention, it was also possible to make the RM residual content halved compared to the comparative medium C1 + RM1.

Example  6

The LC medium described in Example 5 comprising 0.3% RM1 in LC mixtures N1 to N4 or C1 was introduced into a VA e / o test cell as described above. RM was polymerized by irradiating the cell with UV light having a wavelength of 365 nm and an intensity of 50 mW / cm 2 for various periods while applying a 24 V (AC) voltage.

For each test cell, the pretilt angle was measured as indicated above. The pretilt angles achieved in each case over various exposure times are summarized in Table 2 below.

As can be seen from Table 2, the LC medium according to the invention comprises a LC mixture N1, N2, N3 or N4 according to the invention rather than by an LC medium comprising a comparative mixture C1. Could be achieved by Table 2 also shows that after a significantly shorter exposure time the corresponding pretilt angles could already be achieved in LC media comprising LC mixtures N1 to N4 according to the invention rather than by LC media comprising comparative mixture C1. It is shown by.

Thus, for example, Comparative medium C1 + RM1 exhibited a tilt angle of 82.7 ° after an exposure time of 120 seconds. On the other hand, for the LC medium N1 + RM1 according to the invention a smaller tilt angle of 82.3 ° was achieved after only 60 seconds, indicating that it was possible to halve the exposure time compared to the comparative medium.

After an exposure time of 360 seconds, a tilt angle of 74.1 ° was achieved for the comparative medium C1 + RM1. On the other hand, in the case of LC media N2 + RM1, N3 + RM1 and N4 + RM1 according to the invention, a comparable value was achieved only 120 seconds, ie after the third exposure time.

Claims (20)

Use of an LC mixture comprising at least one compound of formula (I) in liquid crystal (LC) displays of the PS (polymer stabilization) or PSA (polymer sustained alignment) type:
(I)

Each radical in the formula has the following meanings:
R ¹ and R ² each independently represent an alkyl having from 1 to 12 carbon atoms, wherein also one or two non-adjacent CH ₂ groups are -O-, -CH in such a way that the O atoms are not directly connected to each other. May be replaced by = CH-, -CO-, -OCO- or -COO-, preferably alkyl or alkoxy having 1 to 6 carbon atoms,
A ¹ , A ² , A ³ and A ⁴ are each independently of the other

or

Lt; / RTI &gt;
1, 2 or 3 of A ¹ , A ² , A ³ and A ⁴ are also

or

Lt; / RTI &gt;
L ¹ and L ² each independently represent H, F, Cl, OCF ₃ , CF ₃ , CH ₂ F or CHF ₂ ,
Z ^1, Z ² and Z ³ are each independently _{-COO-, -OCO-, -CF 2 O-,} -OCF 2 each other _{-, -CH 2 O-, -OCH 2} -, -SCH 2 -, -CH ₂ S-, -CH ₂ CH _2- , -C ₂ F _4- , -CH ₂ -CF _2- , -CF ₂ CH ₂ -,-(CH ₂ ) _z- , -CH = CH-, -CF = CF—, —CH═CF—, —CF═CH—, —C≡C—, —CH═CHCH ₂ O—, or a single bond, where m = 0, Z ¹ and Z ² are simultaneously single Does not represent a bond,
z represents 3, 4, 5 or 6,
m represents 0 or 1. The method of claim 1,
The compound of formula (I) is selected from the group consisting of the compounds of formula (I1 to I15).

Where
Alkyl and alkyl ^* each independently represent a straight chain alkyl radical having 1 to 12 carbon atoms,
(O) represents an oxygen atom or a single bond,
(CH = CH) represents an ethenylene group or a single bond,
L represents H or F. The method according to claim 1 or 2,
The LC mixture further comprises at least one compound of the formulas CY and / or PY and / or LY in addition to the compound of formula I:
[Formula CY]

[Formula PY]

[Formula LY]

Each radical in the formula has the following meanings:
a represents 1 or 2,
b represents 0 or 1,
f represents 0 or 1,

Is

Lt; / RTI &gt;

Is

Lt; / RTI &gt;
R ¹ and R ² each independently represent an alkyl having from 1 to 12 carbon atoms, wherein also one or two non-adjacent CH ₂ groups are -O-, -CH in such a way that the O atoms are not directly connected to each other. May be replaced by = CH-, -CO-, -OCO- or -COO-,
Z ^x and Z ^y are each independently from each other -CH ₂ CH _{2 -, -CH = CH-, -CF 2} O-, -OCF 2 -, -CH 2 O-, -OCH 2 -, -COO-, - OCO-, -C ₂ F _4- , -CF = CF-, -CH = CHCH ₂ O- or a single bond,
L ¹ To L ⁴ each independently represent F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F or CHF ₂ . The method according to any one of claims 1 to 3,
The LC mixture comprises, in addition to the compound of formula I, at least one compound of formula ZK
[Formula ZK]

Each radical in the formula has the following meanings:

Is

Lt; / RTI &gt;

Is

Lt; / RTI &gt;
R ³ and R ⁴ are each independently alkyl having 1 to 12 carbon atoms, wherein also one or two non-adjacent CH ₂ groups are each represented by -O-, -CH = in such a way that no O atoms are directly connected to each other. May be replaced by CH-, -CO-, -OCO- or -COO-,
^Y Z is _{-CH 2 CH 2 -, -CH =} CH-, -CF 2 O-, -OCF 2 -, -CH 2 O-, -OCH 2 -, -COO-, -OCO-, -C 2 F _4- , -CF = CF-, -CH = CHCH ₂ O- or a single bond. The method according to any one of claims 1 to 4,
The LC mixture comprises, in addition to the compound of formula I, at least one compound of formula DK
[Formula DK]

Each radical in the formula has the same meaning in each case to be the same or different:
R ⁵ and R ⁶ has one of the meanings described for R ¹ independently from each other, respectively,

Is

Lt; / RTI &gt;

Is

Indicates. 6. The method according to any one of claims 1 to 5,
The LC mixture comprises, in addition to the compound of formula I, at least one compound of formula T:
[Formula T]

Where
R ⁵ and R ⁶ has one of the meanings described for R ¹ independently from each other, respectively,

Each independently of each other

Wherein L ⁵ represents F or Cl, preferably F, and L ⁶ represents F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F or CHF ₂ , preferably F. The method according to any one of claims 1 to 6,
The LC mixture comprises 1 to 25% of at least one compound of formula (I). The method according to any one of claims 1 to 7,
And said LC mixture comprises at least one compound selected from the group consisting of formula CY with a 1, formula PY with b 0 and formula LY with f 0, in a total concentration of 1 to 60%. The method according to any one of claims 1 to 8,
And said LC mixture comprises at least one compound selected from the group consisting of Formula CY, wherein a is 2, and Formula PY, wherein b is 1, at a total concentration of 1 to 60%. The method according to any one of claims 1 to 9,
And said LC mixture comprises at least one compound selected from the group consisting of formulas ZK1, ZK2, ZK5, ZK6, DK1, DK2, DK4, DK5, B1 and T1 in a total concentration of 1 to 60%. The method according to any one of claims 1 to 10,
And said LC mixture comprises at a total concentration of 1 to 50% of at least one compound selected from the group consisting of Formula CY, and Formula T, wherein a is 2 and R ¹ and R ² are alkyl or alkenyl groups. Polymerizable component A) comprising at least one polymerizable compound, and
Liquid crystal component B) consisting of an LC mixture according to any of the preceding claims.
LC medium comprising a. Polymers obtainable by polymerization of polymerizable component A) comprising at least one polymerizable compound, and
Liquid crystal component B) consisting of an LC mixture according to any of the preceding claims.
LC medium comprising a. Use of an LC medium according to claim 12 or 13 in PS and PSA displays which produces a tilt angle in the LC medium by in situ polymerization of the polymerizable compound (s) in the PSA display by application of an electric or magnetic field. LC display of type PS or PSA containing an LC mixture or LC medium according to claim 1. The method of claim 15,
LC display, which is a PSA-VA, PS-IPS or PS-FFS display. Two substrates wherein at least one substrate is translucent and at least one substrate is an electrode layer; And
A polymerized component, which is located between the substrates and can be obtained by polymerizing one or more polymerizable compounds in an LC medium between substrates of an LC cell by the application of a voltage, and any one of claims 1 to 11. Layer of LC medium comprising a low-molecular weight component which is an LC mixture according to
LC display containing LC cells consisting of. The LC mixture according to any one of claims 1 to 11 is mixed with one or more polymerizable compounds and optionally further liquid crystal compounds and / or additives and the resulting mixture into an LC cell as described in claim 17. 18. A process for producing an LC display according to any one of claims 15 to 17 by introducing and polymerizing the polymerizable compound (s) by application of a voltage. The method according to any one of claims 1 to 17,
Use, LC medium or LC display, wherein said polymerizable component comprises one or more polymerizable compounds of formula (I ^* ):
[Formula I ^* ]
R ^a -B ^1- (Z ^b -B ² ) _m -R ^b
Each radical in the formula has the following meanings:
R ^a and R ^b each independently represent P, P-Sp-, H, halogen, SF ₅ , NO ₂ , a carbon group or a hydrocarbon group, wherein at least one of the radicals R ^a and R ^b is P or P-Sp -Represent or contain groups,
P represents in each case the same or differently polymerizable groups,
Sp represents the same or different in each case a spacer group or a single bond,
B ¹ and B ² each independently represent an aromatic, heteroaromatic, cycloaliphatic or heterocyclic group having preferably 4 to 25 ring atoms, which may also contain fused rings and are mono-substituted by L or Can be substituted
L represents P-Sp-, H, OH, CH ₂ OH, halogen, SF ₅ , NO ₂ , carbon group or hydrocarbon group,
Z ^b is the same or different at each occurrence: -O-, -S-, -CO-, -CO-O-, -OCO-, -O-CO-O-, -OCH _2- , -CH ₂ O- , -SCH _2- , -CH ₂ S-, -CF ₂ O-, -OCF _2- , -CF ₂ S-, -SCF ₂ -,-(CH ₂ ) _n 1-, -CF ₂ CH ₂ -,- CH ₂ CF ₂ -,-(CF ₂ ) _n 1-, -CH = CH-, -CF = CF-, -C≡C-, -CH = CH-COO-, -OCO-CH = CH-, CR ⁰ R ⁰⁰ or a single bond,
R ⁰ and R ⁰⁰ each independently represent H or alkyl having 1 to 12 carbon atoms,
m represents 0, 1, 2, 3 or 4,
n1 represents 1, 2, 3 or 4. The method of claim 19,
Use, LC medium or LC display, wherein the concentration of said polymerizable component is at least 0.01% and at most 5%.